Titanium alloy wire the grade of filler wire should be selected according to the base material, generally using the principle of homogeneity with the base material, sometimes in order to improve the plasticity of the joint, can also choose to base material less alloyed degree of the wire. Wire diameter should be selected according to base material thickness. It is best to choose cerium tungsten pole, its diameter according to the thickness of titanium alloy tube wall, generally in 1.0 ~ 3.0mm, tungsten extreme should be ground into 30 ~ 45 degree cone.
Groove form selection principle to minimize the number of welding layers and welding metal. With the increase of the number of welding layers, the cumulative suction placement of the welds increased, which affected the performance of the welding joint. In addition, the welding pool size of titanium and titanium alloy was larger, so the specimen was ordered with v-type 70-80 ° groove.
In order to reduce welding deformation, positioning welding was carried out before welding. Generally, the distance of positioning welding was 100~150mm and the length was 10~ 15mm. The welding wire, welding process parameters and gas protection conditions used in positioning welding shall be the same as those used in welding joints. Clearance 0~2mm, blunt edge 0~1.0mm.
